<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>
<body>
  


  <script>

  let arr =[15, 19, 21, 33, 18, 24]  
  let sum =0 
   
   for (let i = 0; i < arr.length; i++) {
    sum+=arr[i]
    
   }
  let average = sum/arr.length
  document.write(average);
  </script>
</body>
</html>